I wouldn't get too close, as others have said, if you spook them away from a roost it's done for that area for the season. Our birds roost in a general area, but not the same tree nightly. I have watched birds going to roost and they usually hang around within 200-400 yards of the roost within 2-3 hrs of fly up then move to the roost pretty quickly when ready to go up. I usually set up in that 200-300 yard circle and soft call. I have had several bird just show up with no gobbling and others come just raising caine. if you know which way he went in the morning he'll often return that way. Hens will often call more and give their location away in the early season. if you hear hens set up on them....he's with them, but not talking because he has other things on his mind. Call them in and he'll come. One last thing, if your in hill country then be higher than the roost, they often work up hill to fly up.